Investigation of the Shape of InGaAs/GaAs Quantum Dots

Published

January 1, 2003

Author(s)

Susan Y. Lehman, Alexana Roshko, Richard Mirin, John E. Bonevich

Abstract

Three samples of self-assembled In_0.44Ga_0.56As quantum dots (QDs) grown on (001) GaAs by molecular beam epitaxy (MBE) were studied using atomic force microscopy (AFM)) and high-resolution transmission electron microscopy (TEM) in order to characterize the height, faceting, and densities of the QDs. The cross-sectional TEM images show both pyramidal dots and dots with multiple side facets. Multiple faceting has been observed only in dots more than 8.5 nm in height and allows increased dot volume without a substantial increase in base area. Addition of a GaAs capping layer is found to increase the diameter of the QDs from roughly 40 nm to as much as 200 nm. The areal QD density is found to vary up to 50 % over the central 2 cm x 2 cm section of wafer and as much as 23 % on a length scale of micrometers.

Proceedings Title

Proc., Mater. Res. Soc. Symp.

Volume

737

Conference Dates

December 2-6, 2002

Conference Location

Boston, MA, USA

Pub Type

Conferences

Keywords

InGaAs, quantum dots

Citation

Lehman, S. , Roshko, A. , Mirin, R. and Bonevich, J. (2003), Investigation of the Shape of InGaAs/GaAs Quantum Dots, Proc., Mater. Res. Soc. Symp., Boston, MA, USA (Accessed January 30, 2026)